Polythiourethane polymerizable composition and method for producing optical resin by using same

ABSTRACT

A resin composition excellent in tintability and resin strength, a resin obtained by curing such a resin composition, and an optical component is provided. A polymerizable composition containing an isocyanate compound suitably used for transparent resin materials, at least one polythiol compound which may have one or more (poly)sulfide bonds in a molecule, and at least one polyhydroxy compound having two or more hydroxy groups in a molecule and/or at least one (poly)hydroxy(poly)mercapto compound having one or more hydroxy groups and one or more thiol groups is used.

TECHNICAL FIELD

The present invention relates to a polymerizable composition, a resinand an optical component.

BACKGROUND ART

Since a plastic lens is lightweight and hardly broken as compared to aninorganic lens, and can be tinted, in late years, it has quickly comeinto wide use as an optical component of a spectacle lens, a camera lensand the like.

A spectacle lens has been required to have many functions such as (3)excellent heat resistance, (4) easy tintability, (5) resin strengthcapable of enduring processing and the like in addition to opticalperformance such as (1) high refractive index, (2) high Abbe's number.Various resin materials for lenses have hitherto been developed and usedaccordingly.

Of such materials, a polythiourethane resin has been developed as arepresentative example (refer to Patent Documents 1 and 2).

Furthermore, a polythiourethane resin using an isocyanate compoundhaving a specific chemical structure is excellent in high refractiveindex, high Abbe's number, high heat resistance and impact resistance,and made into a plastic lens which is highly excellent in the balancethereof (refer to Patent Document 3).

On the other hand, in recent years, fashionability has been demanded ina spectacle lens so that a tinted lens has been increasingly demanded.When tintability is said to be good, the tinting temperature can belowered and a load on a spectacle lens can be reduced. However, sincetintability and heat resistance of a base material are in a tradeoffrelationship, a lens having heat resistance without having any problemin practical use and excellent in tintability has been in demand.Furthermore, since fashionability is further pursued, a resin has beensubjected to various processings. However, when resin strength is notsufficient, the resin might be broken upon processing or the yield ratebecomes worsened. For that reason, resin strength has been demanded tobe further improved.

As described above, a plastic lens has been exemplified, but in apolythiourethane resin, tintability and resin strength have beendemanded to be improved.

Patent Document 1: Japanese Patent Laid-open No. 1990-270859

Patent Document 2: Japanese Patent Laid-open No. 1995-252207

Patent Document 3: Japanese Patent Laid-open No. 1991-124722

DISCLOSURE OF THE INVENTION

A problem of the present invention is to provide a composition giving aresin excellent in tintability and having sufficient resin strength ascompared to a conventional resin.

In order to solve the above problem, the present inventors haveconducted an extensive study and as a result, have found that apolythiourethane resin obtainable by polymerizing a polymerizablecomposition containing (A) an alicyclic isocyanate compound representedby the following formula (1) and/or formula (2), (B) an isocyanatecompound containing at least one selected from a group of compounds informula (3), formula (4) or formula (5), (C) at least one polythiolcompound which may have one or more (poly) sulfide bonds in a molecule,and (D) at least one polyhydroxy compound having two or more hydroxygroups in a molecule and/or at least one (poly)hydroxy(poly)mercaptocompound having one or more hydroxy groups and one or more thiol groupshas fully satisfied the required physical properties. Thus, the presentinvention has been completed.

That is, the present invention relates to:

[1] a polymerizable composition containing (A) an alicyclic isocyanatecompound represented by the following formula (1) and/or the followingformula (2),

(in the formula (1), n represents an integer equal to or larger than 0and equal to or smaller than 3)

(B) an isocyanate compound containing at least one selected from a groupof compounds consisting of the following formula (3), the followingformula (4) and the following formula (5), [Chem. 3]OCN—(CH₂)m-NCO  (3)(in the formula (3), m represents an integer equal to or larger than 2and equal to or smaller than 10)

(in the formula (4), p represents an integer equal to or larger than 2and equal to or smaller than 10)

(in the formula (5), q represents an integer equal to or larger than 2and equal to or smaller than 10)

(C) at least one polythiol compound which may have one or more(poly)sulfide bonds in a molecule, and

(D) at least one polyhydroxy compound having two or more hydroxy groupsin a molecule and/or at least one (poly)hydroxy(poly)mercapto compoundhaving one or more hydroxy groups and one or more thiol groups;

[2] the polymerizable composition as set forth in [1], wherein the (A)is an alicyclic isocyanate compound represented by the following formula(6) and/or the above formula (2), and

the (B) is at least one isocyanate compound selected from a group ofcompounds consisting of the above formula (3) (m=6), the above formula(4) (p=6) and the above formula (5) (q=6);

[3] the polymerizable composition as set forth in [1] or [2], wherein100×A/(A+B+C) is not less than 0.1% but not more than 40% when the molenumbers of the hydroxy group and the thiol group in the (D) polyhydroxycompound having two or more hydroxy groups in a molecule and/or the(poly)hydroxy(poly)mercapto compound having one or more hydroxy groupsand one or more thiol groups are respectively taken as A and B, and themole number of the thiol group in the (C) polythiol compound which mayhave one or more (poly)sulfide bonds in a molecule is taken as C;

[4] the polymerizable composition as set forth in [3], wherein the (C)polythiol compound which may have one or more (poly) sulfide bonds in amolecule contains at least one of4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane,2,5-bismercaptomethyl-1,4-dithiane, bis(mercaptoethyl)sulfide,1,1,3,3-tetrakis(mercaptomethylthio)propane,4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane,5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane and4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane;

[5] the polymerizable composition as set forth in [3] or [4], whereinthe (D) polyhydroxy compound having two or more hydroxy groups in amolecule and/or the (poly)hydroxy(poly)mercapto compound having one ormore hydroxy groups and one or more thiol groups contains at least oneof 2-mercaptoethanol, 3-mercapto-1,2-propanediol, pyrogallol, ethyleneglycol and polycaprolactonediol;

[6] the polymerizable composition as set forth in [5], wherein the (A)is an alicyclic isocyanate compound represented by the following formula(6) and/or the above formula (2),

the (B) is at least one isocyanate compound selected from a group ofcompounds consisting of the above formula (3) (m=6), the above formula(4) (p=6) and the above formula (5) (q=6),

the (C) polythiol compound which may have one or more (poly)sulfidebonds in a molecule is at least one of4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane,4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane,5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane and4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and

the (D) polyhydroxy compound having two or more hydroxy groups in amolecule and/or the (poly)hydroxy(poly)mercapto compound having one ormore hydroxy groups and one or more thiol groups is 2-mercaptoethanol;

[7] a method for producing a resin, wherein the polymerizablecomposition as set forth in any one of [1] to [6] is polymerized;

[8] a resin obtained by polymerizing the polymerizable composition asset forth in any one of [1] to [6];

[9] an optical component consisting of the resin as set forth in [8];

[10] a lens consisting of the optical component as set forth in [9];

[11] a spectacle lens consisting of the lens as set forth in [10];

[12] use of the polymerizable composition as set froth in any one of [1]to [6] as an optical component; and

[13] use of the resin obtained by polymerizing the polymerizablecomposition as set forth in any one of [1] to [6] as an opticalcomponent.

BEST MODE FOR CARRYING OUT THE INVENTION

The polymerizable composition of the present invention contains thefollowing components,

(A) an alicyclic isocyanate compound represented by the followingformula (1) and/or the following formula (2),

(in the formula (1), n represents an integer equal to or larger than 0and equal to or smaller than 3)

(B) an isocyanate compound containing at least one selected from a groupof compounds consisting of the following formula (3), the followingformula (4) and the following formula (5), [Chem. 10]OCN—(CH₂)m-NCO  (3)

(in the formula (3), m represents an integer equal to or larger than 2and equal to or smaller than 10)

(in the formula (4), p represents an integer equal to or larger than 2and equal to or smaller than 10)

(in the formula (5), q represents an integer equal to or larger than 2and equal to or smaller than 10)

(C) at least one polythiol compound which may have one or more(poly)sulfide bonds in a molecule, and

(D) at least one polyhydroxy compound having two or more hydroxy groupsin a molecule and/or at least one (poly)hydroxy(poly)mercapto compoundhaving one or more hydroxy groups and one or more thiol groups.

Furthermore, the resin of the present invention is obtained bypolymerizing the aforementioned polymerizable composition.

Further specifically, the polythiourethane resin of the presentinvention can be produced by mixing and polymerizing the polymerizablecomposition containing

(A) an alicyclic isocyanate compound represented by the above formula(1) and/or the formula (2),

(B) an isocyanate compound containing at least one selected from a groupof compounds consisting of the above formula (3), the above formula (4)and the above formula (5),

(C) at least one polythiol compound which may have one or more(poly)sulfide bonds in a molecule, and

(D) at least one polyhydroxy compound having two or more hydroxy groupsin a molecule and/or at least one (poly)hydroxy(poly)mercapto compoundhaving one or more hydroxy groups and one or more thiol groups.

A method for producing the polythiourethane resin of the presentinvention and the polythiourethane resin obtained by this method areexcellent in tintability, and has sufficient resin strength, as comparedto conventional resins.

Next, the polymerizable composition in the present invention will bedescribed in detail by referring to concrete examples, but the presentinvention is not restricted to the compounds as exemplified below.Furthermore, in each component of the present invention, exemplifiedcompounds may be used singly or a plurality of the compounds may be usedin combination.

First, the isocyanate compound according to the present invention willbe described.

Examples of the alicyclic isocyanate compound represented by the aboveformula (1) include 2,5-bis(isocyanate)-bicyclo[2,2,1]heptane,2,6-bis(isocyanate)-bicyclo[2,2,1]heptane,2,5-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane,2,6-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane,2,5-bis(isocyanatoethyl)-bicyclo[2,2,1]heptane,2,6-bis(isocyanatoethyl)-bicyclo[2,2,1]heptane and the like. Of thesecompounds, one or two or more kinds can be used.

More specifically, as the alicyclic isocyanate compound represented bythe above formula (1),2,5(6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane represented by thefollowing formula (6) can be used.

Herein, 2,5(6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane contains atleast any one of 2,5-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane and2,6-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, and may concretelycontain any one of the following (i) to (iii),

(i) a single product of 2,5-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane

(ii) a single product of2,6-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, and

(iii) a mixture of 2,5-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane and2,6-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane.

Furthermore, examples of the alicyclic isocyanate compound representedby the above formula (2) include 1,2-bis(isocyanatomethyl)cyclohexane,1,3-bis(isocyanatomethyl)cyclohexane,1,4-bis(isocyanatomethyl)cyclohexane and the like. Of these compounds,one or two or more kinds can be used.

Examples of the isocyanate compound represented by the above formula (3)include 1,2-ethylene diisocyanate, 1,3-propylene diisocyanate,1,4-butylene diisocyanate, 1,6-hexamethylene diisocyanate,1,7-heptamethylene diisocyanate, 1,8-octamethylene diisocyanate,1,9-nonamethylene diisocyanate, 1,10-decamethylene diisocyanate and thelike. Of these compounds, one or two or more kinds can be used.

The compounds represented by the above formula (4) and the above formula(5) can be easily obtained by using the compound represented by theabove formula (3) as a raw material. The obtained compound may bepurified, prior to use, or may be mixed with the compound in the aboveformula (3) that is a raw material monomer. Furthermore, otherisocyanate compounds may be contained.

Next, components (C) and (D) will be described.

Examples of (C) the polythiol compound which may have one or more(poly)sulfide bonds in a molecule include aliphatic polythiol compoundssuch as methanedithiol, 1,2-ethanedithiol, 1,3-propanedithiol,2,2-propanedithiol, 1,6-hexanedithiol, 1,2,3-propanetrithiol,1,1-cyclohexanedithiol, 1,2-cyclohexanedithiol,4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane,4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane,5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane,4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane,tetrakis(mercaptomethyl)methane,1,1,3,3-tetrakis(mercaptomethylthio)propane,1,1,2,2-tetrakis(mercaptomethylthio)ethane,1,1,5,5-tetrakis(mercaptomethylthio)-3-thiapentane,1,1,6,6-tetrakis(mercaptomethylthio)-3,4-dithiahexane,2,2-bis(mercaptomethyl)-1,3-propanedithiol and the like; aliphaticpolythiol compounds having a (poly) sulfide bond such asbis(mercaptomethyl)sulfide, bis(mercaptomethyl)disulfide,bis(mercaptoethyl)sulfide, bis(mercaptoethyl)disulfide,bis(mercaptopropyl)sulfide, bis(mercaptopropyl)disulfide,bis(mercaptomethylthio)methane, tris(mercaptomethylthio)methane,bis(mercaptoethylthio)methane, tris(mercaptoethylthio)methane,bis(mercaptopropylthio)methane, 1,2-bis(mercaptomethylthio)ethane,1,2-bis(mercaptoethylthio)ethane, 1,3-bis(mercaptopropylthio)ethane,1,3-bis(mercaptomethylthio)propane, 1,3-bis(mercaptoethylthio)propane,1,3-bis(mercaptopropylthio)propane,1,2,3-tris(mercaptomethylthio)propane,1,2,3-tris(mercaptoethylthio)propane,1,2,3-tris(mercaptopropylthio)propane,tetrakis(mercaptomethylthio)methane,tetrakis(mercaptoethylthiomethyl)methane,tetrakis(mercaptopropylthiomethyl)methane, 2,5-dimercapto-1,4-dithiane,2,5-bismercaptomethyl-1,4-dithiane and the like;

aliphatic polythiol compounds having an ester bond such as ethyleneglycol bis(2-mercaptoacetate), ethylene glycolbis(3-mercaptopropionate), diethylene glycol (2-mercaptoacetate),diethylene glycol (3-mercaptopropionate),2,3-dimercapto-1-propanol(3-mercaptopropionate),3-mercapto-1,2-propanediol bis(2-mercaptoacetate),3-mercapto-1,2-propanediol di(3-mercaptopropionate), trimethylolpropanetris(2-mercaptoacetate), trimethylolpropane(3-mercaptopropionate),trimethylolethane tris(2-mercaptoacetate), trimethylolethanetris(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate),pentaerythritol (3-mercaptopropionate), glycerinetris(2-mercaptoacetate), glycerine tris(3-mercaptopropionate),1,4-cyclohexanediol bis(2-mercaptoacetate), 1,4-cyclohexanediolbis(3-mercaptopropionate), hydroxymethylsulfide bis(2-mercaptoacetate),hydroxymethylsulfide bis(3-mercaptopropionate),hydroxyethylsulfide(2-mercaptoacetate),hydroxyethylsulfide(3-mercaptopropionate),hydroxymethyldisulfide(2-mercaptoacetate),hydroxymethyldisulfide(3-mercaptopropionate), thioglycolic acidbis(2-mercaptoethyl ester), thiodipropionic acid bis(2-mercaptoethylester) and the like; and

compounds having an aromatic ring such as 1,2-dimercaptobenzene,1,3-dimercaptobenzene, 1,4-dimercaptobenzene,1,2-bis(mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene,1,2-bis(mercaptoethyl)benzene, 1,4-bis(mercaptoethyl)benzene,1,2,3-trimercaptobenzene, 1,2,4-trimercaptobenzene,1,3,5-trimercaptobenzene, 1,2,3-tris(mercaptomethyl)benzene,1,2,4-tris(mercaptomethyl)benzene, 1,3,5-tris(mercaptomethyl)benzene,1,2,3-tris(mercaptoethyl)benzene, 1,3,5-tris(mercaptoethyl)benzene,1,2,4-tris(mercaptoethyl)benzene, 2,5-toluenedithiol,3,4-toluenedithiol, 1,4-naphthalenedithiol, 1,5-naphthalenedithiol,2,6-naphthalenedithiol, 2,7-naphthalenedithiol,1,2,3,4-tetramercaptobenzene, 1,2,3,5-tetramercaptobenzene,1,2,4,5-tetramercaptobenzene, 1,2,3,4-tetrakis(mercaptomethyl)benzene,1,2,3,5-tetrakis(mercaptomethyl)benzene,1,2,4,5-tetrakis(mercaptomethyl)benzene,1,2,3,4-tetrakis(mercaptoethyl)benzene,1,2,3,5-tetrakis(mercaptoethyl)benzene,1,2,4,5-tetrakis(mercaptoethyl)benzene, 2,2′-dimercaptobiphenyl,4,4′-dimercaptobiphenyl and the like. One or two or more kinds of thesecompounds can be used.

It is further preferable that (C) the polythiol compound which may haveone or more (poly)sulfide bonds in a molecule of these compounds may beof a construction containing at least one of4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane,2,5-bismercaptomethyl-1,4-dithiane, bis(mercaptoethyl)sulfide,1,1,3,3-tetrakis(mercaptomethylthio)propane,4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane,5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane and4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane.

Meanwhile, examples of the polyhydroxy compound having two or morehydroxy groups in a molecule of (D) the polyhydroxy compound having twoor more hydroxy groups in a molecule and/or the(poly)hydroxy(poly)mercapto compound having one or more hydroxy groupsand one or more thiol groups include ethylene glycol, 1,3-propanediol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol,propylene glycol, dipropylene glycol, triethylene glycol, butyleneglycol, glycerine, trimethylol ethane, trimethylol propane,pentaerythritol, sorbitol, erythritol, xylitol, mannitol,polycaprolactonediol, polyethylene glycol, bisphenol A, bisphenol F,bisphenol A-bis(2-hydroxyethyl ether), tetrabromobisphenol A,tetrabromophenol A-bis(2-hydroxyethyl ether), pyrogallol and the like.However, the present invention is not restricted only to theseexemplified compounds. These compounds may be used singly or incombination of two or more kinds thereof.

Furthermore, examples of the (poly)hydroxy(poly)mercapto compound havingone or more hydroxy groups and one or more thiol groups of (D) thepolyhydroxy compound having two or more hydroxy groups in a moleculeand/or the (poly)hydroxy(poly)mercapto compound having one or morehydroxy groups and one or more thiol groups include aliphatic compoundssuch as 2-mercaptoethanol, 3-mercapto-1,2-propanedithiol,1,3-dimercapto-2-propanol, 2,3-dimercapto-1-propanol,1,2-dimercapto-1,3-butanediol and the like; (poly)hydroxy(poly)mercaptocompounds having an ester group such as pentaerythritolmono(3-mercaptopropionate), pentaerythritol bis(3-mercaptopropionate),pentaerythritol tris(3-mercaptopropionate) and the like; and(poly)hydroxy(poly)mercapto compounds having an aromatic ring such as4-mercaptophenol, 2,4-dimercaptophenol and the like. One or two or morekinds thereof can be used.

More concretely, it is preferable that (D) the polyhydroxy compoundhaving two or more hydroxy groups in a molecule and/or the(poly)hydroxy(poly)mercapto compound having one or more hydroxy groupsand one or more thiol groups is of a construction containing at leastone of 2-mercaptoethanol, 3-mercapto-1,2-propanediol, pyrogallol,ethylene glycol and polycaprolactonediol.

As the proportion of the alicyclic isocyanate compound represented bythe above formula (1) and/or the above formula (2), at least oneisocyanate compound selected from a group of compounds of the aboveformula (3), the above formula (4) or the above formula (5), thepolythiol compound which may have one or more (poly) sulfide bonds in amolecule, the polyhydroxy compound having two or more hydroxy groups ina molecule, and/or the (poly)hydroxy(poly)mercapto compound having oneor more hydroxy groups and one or more thiol groups, the molar ratio ofthe NCO/(SH+OH) functional group is usually in the range of 0.5 to 3.0,preferably in the range of 0.5 to 1.5, and particularly preferably inthe range of 0.8 to 1.2.

The polymerizable composition of the present invention can be, forexample, of the following construction: (A) is an alicyclic isocyanatecompound represented by the following formula (6) and/or the aboveformula (2);

(B) is at least one isocyanate compound selected from a group ofcompounds consisting of the above formula (3) (m=6), the above formula(4) (p=6) and the above formula (5) (q=6);

and containing (C) at least one polythiol compound which may have one ormore (poly)sulfide bonds in a molecule; and

(D) at least one polyhydroxy compound having two or more hydroxy groupsin a molecule and/or at least one (poly)hydroxy(poly)mercapto compoundhaving one or more hydroxy groups and one or more thiol groups.

Furthermore, the polymerizable composition of the present invention maybe of a construction containing the following components: containing analicyclic isocyanate compound represented by the above formula (6)and/or the above formula (2); and

at least one isocyanate compound selected from a group of compoundsconsisting of the above formula (3) (m=6), the above formula (4) (p=6)and the above formula (5) (q=6);

wherein (C) the polythiol compound which may have one or more(poly)sulfide bonds in a molecule is at least one of4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane,4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane,5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane and4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane;

while (D) the polyhydroxy compound having two or more hydroxy groups ina molecule and/or the (poly)hydroxy(poly)mercapto compound having one ormore hydroxy groups and one or more thiol groups is 2-mercaptoethanol.

Meanwhile, of the compounds as cited above, when2,5(6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane as an alicyclicisocyanate compound represented by the above formula (1),1,6-hexamethylene diisocyanate as a compound represented by the aboveformula (3), 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane as (C) apolythiol compound which may have one or more (poly) sulfide bonds in amolecule and 2-mercaptoethanol as (D) a polyhydroxy compound having twoor more hydroxy groups in a molecule and/or a(poly)hydroxy(poly)mercapto compound having one or more hydroxy groupsand one or more thiol groups are used in combination thereof, a resinobtainable by polymerizing these compounds is excellent in tintabilityand resin strength, and results in sufficiently satisfying refractiveindex, Abbe's number and heat resistance.

Further, (D) the polyhydroxy compound having two or more hydroxy groupsin a molecule and/or the (poly)hydroxy(poly)mercapto compound having oneor more hydroxy groups and one or more thiol groups is a compoundcontaining a hydroxy group in a molecular structure.

When the mole numbers of the hydroxy group and the thiol group in (D)the polyhydroxy compound having two or more hydroxy groups in a moleculeand/or the (poly)hydroxy(poly)mercapto compound having one or morehydroxy groups and one or more thiol groups are respectively taken as Aand B, and the mole number of the thiol group in (C) the polythiolcompound which may have one or more (poly)sulfide bonds in a molecule istaken as C, as for the upper limit of the content of the hydroxy group,100×A/(A+B+C) (%) is, for example, not more than 40%, preferably notmore than 35%, and further preferably not more than 30%. In this manner,a resin particularly excellent in the balance between tintability andresin strength is obtained.

Meanwhile, the lower limit of the content of the hydroxy group is notparticularly limited, but the value of the above 100×A/(A+B+C) (%) canbe, for example, not less than 0.1%, preferably not less than 3.0% andfurther preferably not less than 5.0%.

A resin modifier can be added to the polymerizable composition of thepresent invention, in order to regulate optical physical properties suchas refractive index, specific gravity and the like, impact resistance ofthe obtained resin, the viscosity of the polymerizable composition, andthe like.

Furthermore, in curing the polymerizable composition of the presentinvention by the polymerization, various substances may also be added inthe same manner as in a known molding method depending on the purpose.Examples of the substance include a chain extension agent, acrosslinking agent, a light stabilizer, an ultraviolet absorbent, ananti-oxidant, an anti-coloring agent, a blueing agent and the like.Incidentally, the curing method is not particularly limited, but, forexample, heat curing or the like can be used.

Furthermore, a known reaction catalyst can be properly added for thepurpose of adjusting the desired reaction rate. Examples of the catalystto be preferably used include tin compounds such as dibutyltindilaurate, dibutyltin dichloride, dimethyltin dichloride, tetramethyldiacetoxy distannoxane, tetraethyl diacetoxy distannoxane, tetrapropyldiacetoxy distannoxane, tetrabutyl diacetoxy distannoxane and the like;or amine compounds such as a tertiary amine and the like as aurethanization catalyst. These compounds can be used singly or incombination of two or more kinds. The amount of the catalyst added ispreferably in the range of 0.001 to 1 weight % based on the total weightof monomers of the composition. This range is preferable because theextent of polymerization is excellent and from the viewpoint of pot lifeupon compounding, or transparency, optical physical properties or lightresistance of the obtained resin.

The polymerizable composition of the present invention is cured by thepolymerization. In this manner, the resin of the present invention isobtained. The resin of the present invention is typically obtained bysubjecting the above polymerizable composition to a castingpolymerization. Concretely, various additives such as a catalyst, anultraviolet absorbent, an internal release agent and the like arepreviously mixed with the monomer in use to give a mixed solution. Thismixed liquid is degassed according to a proper method as needed, andthen poured into a mold composed of two pieces of glass plates, a tapeor a gasket for carrying out the polymerization. The pouring viscosityis not particularly limited, but the viscosity of the monomer mixedsolution is preferably from 20 to 1000 mPa·s. The polymerizationconditions at the time of polymerization cannot be restricted since theconditions are greatly different depending on the type of the monomer,the type of the catalyst, the amount thereof, the shape of the mold inuse and the like. But, a thermal polymerization is usually carried outat a temperature of from −20 degrees centigrade to 200 degreescentigrade over 1 to 100 hours.

The polythiourethane resin of the present invention mainly contains aurethane bond and/or a thiocarbamic acid S-alkyl ester bond by anisocyanate group and a hydroxy group and/or a thiol group. However, inaddition thereto, it may further contain an allophanate bond, a ureabond or a biuret bond depending on the purpose. For example, thecrosslinking density is increased by further reacting a urethane bond ora thiocarbamic acid S-alkyl ester bond with an isocyanate group. Suchincreased crosslinking density might bring about desirable results inmany cases. In this case, the reaction temperature is increased to atleast not lower than 100 degrees centigrade, an isocyanate component isalso used in large quantities. Or, amine or the like is partly usedtogether, and a urea bond and a biuret bond can also be employed. When acompound other than a polyol compound reacting with an isocyanatecompound, a polythiol compound and a thiol compound having a hydroxygroup is employed, there is particularly a need to pay attention to thecoloring.

According to the present invention, it was found that thepolythiourethane resin obtainable by polymerizing the polymerizablecomposition containing at least one of a polyisocyanate compound to besuitably used for transparent resin materials, (C) at least onepolythiol compound which may have one or more (poly)sulfide bonds in amolecule, and (D) at least one polyhydroxy compound having two or morehydroxy groups in a molecule and/or at least one(poly)hydroxy(poly)mercapto compound having one or more hydroxy groupsand one or more thiol groups is excellent in tintability and resinstrength, as compared to conventional resins, and has performancesatisfying all of the refractive index, Abbe's number and heatresistance.

For this reason, the thus-obtained polythiourethane resin of the presentinvention is colorless and transparent, and also excellent in opticalphysical properties so that it is suitably used as an optical componentor an optical element material of lens such as a spectacle lens or thelike, a prism, a camera lens, an optical fiber, an information recordingplate, a filter, a light emitting diode and the like.

For example, according to the present invention, a composition and aresin which are excellent in tintability and resin strength as comparedto conventional resins for lenses and provide a resin for a lenssatisfying all of the refractive index, Abbe's number and heatresistance are obtainable.

Furthermore, according to the present invention, as an optical materialin the field using high refractive index materials, a transparentcurable resin excellent in tintability and resin strength is obtained.In particular, a material suitable in the field of optical componentsincluding lenses such as a spectacle lens and the like is obtained.

Incidentally, in order to improve anti-reflection, high hardness grant,wear resistance improvement, improvement of chemical resistance,anti-fogging property grant, fashionability grant or the like, thepolythiourethane lens of the present invention can be subjected tophysical or chemical processes such as surface polishing, antistaticprocess, hard coating process, non-reflective coating process, tintingprocess, photochromic process and the like as needed. A water bath witha disperse dye dispersed therein is usually used for tinting. However,in order to improve the tinting rate and the tinting concentration, atinting bath with a carrier represented by benzyl alcohol added theretomay also be used.

EXAMPLES

The present invention is now illustrated in detail below with referenceto Examples. Incidentally, of performance tests of the obtained resin, areflective index, specific gravity, heat resistance, resin strength andtintability were respectively evaluated in the following manner.

Refractive index (ne) and Abbe's number (ve): They were measured at 20degrees centigrade using a Pulfrich refractometer.

Specific gravity: It was measured according to the Archimedian method.

Heat resistance: Tg (° C.) measured by TMA (Thermo Mechanical Analysis)penetration method (a load of 50 g, a pinpoint of 0.5 mmΦ, a heatingrate of 10 degrees centigrade/min) was take as the heat resistance.

Resin strength: A resin strip with a polythiourethane resin processedinto a dumbbell shape having a thickness of 3 mm, a length of 85 mm anda width of 5 mm using AUTOGRAPH AGS-J (a product of ShimadzuCorporation) was employed. At a temperature of 20 degrees centigrade,the test strip was applied a load at a tensile speed of from 1 mm/min to5 mm/min. At that time, its maximum load (N/mm²) was calculated.

Tintability: To 995 g of pure water were added 1.5 g of a disperse dyefor a spectacle lens [MLP-Blue], 2.0 g of [MLP-Yellow] and 1.5 g of[MLP-Red] (products of Miike Dyes Works Ltd.) as a tinting agent toadjust a dye dispersion. The resulting mixture was heated to 90 degreescentigrade and then a plastic lens piece having a thickness of 9 mm wasimmersed therein at 90 degrees centigrade for 5 minutes for tinting. Thelens piece after being tinted was scanned at a wavelength of 400 to 800nm to measure the transmittance (% T) at 565 nm.

Example 1

50.31 g of 2,5(6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, 10.26 gof 1,6-hexamethylene diisocyanate, 11.91 g of 2-mercaptoethanol, 27.52 gof 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 0.25 g of Zelec UN(an internal release agent) and 0.05 g of Viosorb 583 (an ultravioletabsorbent) were mixed and dissolved at 20 degrees centigrade. 0.15 g ofdibutyltin dichloride was added thereto as a curing catalyst to give auniform solution.

The uniform solution was degassed at 600 Pa for 1 hour, filtered using a1 μm Teflon (registered trademark) filter and poured into a mold framecomposed of a glass mold and a tape. The mold frame was put in an oven,subjected to a temperature elevation slowly from 25 to 120 degreescentigrade for polymerizing over 20 hours. After the polymerization wascompleted, the mold frame was taken out of the oven, and releasedtherefrom to obtain a resin. The obtained resin was further subjected toan annealing process at 120 degrees centigrade for 4 hours.

The obtained resin was excellent such that it was colorless and has hightransparency. The refractive index (ne) thereof was 1.597 and Abbe'snumber (ve) was 41.

Examples 2 to 7

Lenses were prepared with compositions in Table 1 in the same manner asin Example 1. The evaluation results are shown in Table 2. An internalrelease agent, an ultraviolet absorbent and a curing catalyst were alsoused in the same manner.

Comparative Example 1

To 50.6 g of 2,5(6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane weremixed 0.13 g of Zelec UN (product name, an internal release agent), 0.05g of Viosorb 583 (product name, an ultraviolet absorbent), 23.9 g ofpentaerythritol tetrakis(3-mercaptopropionate) and 25.5 g of4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, and the resultingmixture was dissolved. 0.02 g of dibutyltin dichloride as a curingcatalyst was added thereto, and the mixed solution was degassed at 600Pa for 1 hour, filtered using a 1 μm Teflon (registered trademark)filter, and poured into a mold frame composed of a glass mold and atape.

The mold frame was put in an oven, and subjected to a temperatureelevation slowly from 10 to 120 degrees centigrade for polymerizing over18 hours. After the polymerization was completed, the mold frame wastaken out of the oven, and released therefrom to obtain a resin. Theobtained resin was further subjected to an annealing process at 120degrees centigrade for 3 hours.

The obtained resin was excellent such that it was colorless and has hightransparency. The refractive index (ne) thereof was 1.598 and Abbe'snumber (ve) was 41.

TABLE 1 Component (A) Component (B) Component (C) Component (D) Type(mole) Type (mole) Type (mole) Type (mole) H(%) Example 1 (A)-1 0.244(B)-1 0.061 (C)-1 0.106 (D)-1 0.153 24.6 2 (A)-1 0.276 (B)-1 0.031 (C)-10.095 (D)-1 0.169 27.1 3 (A)-1 0.249 (B)-2 0.021 (C)-1 0.115 (D)-1 0.11019.5 4 (A)-1 0.242 (B)-1 0.059 (C)-2 0.076 (D)-1 0.154 25.2 5 (A)-10.272 (B)-1 0.030 (C)-2 0.065 (D)-1 0.179 29.0 6 (A)-1 0.213 (B)-3 0.044(C)-1 0.092 (D)-1 0.128 24.1 7 (A)-2 0.273 (B)-1 0.030 (C)-2 0.082 (D)-10.154 24.2 Comparative (A)-1 0.245 (C)-1 0.098 0.0 Example 1 (C)-3 0.049

Incidentally, Examples 1 to 6 and Comparative Example 1, as 2,5(6)-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane, a mixture of2,5-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane and2,6-bis(isocyanatomethyl)-bicyclo[2,2,1]heptane was used.

Symbols in Table 1 indicate the following.

(A)-1: 2,5(6)-bis(isocyanatomethyl)-bicyclo [2,2,1]heptane

(A)-2: 1,3-bis(isocyanatomethyl)cyclohexane

(B)-1: 1,6-hexamethylene diisocyanate

(B)-2: a compound having p=6 in the above formula (4)

(B)-3: a compound having q=6 in the above formula (5)

(C)-1: 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (C)-2:

4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane

(C)-3: pentaerythritol tetrakis(3-mercaptopropionate)

(D)-1: 2-mercaptoethanol

H: the proportion (%) of the mole number of the hydroxy group occupiedin the total mole numbers of the thiol group and the hydroxy group,100×A/(A+B+C), when the mole numbers of the hydroxy group and the thiolgroup in a polyhydroxy compound having two or more hydroxy groups in amolecule and/or a (poly)hydroxy(poly)mercapto compound having one ormore hydroxy groups and one or more thiol groups are respectively takenas A and B, and the mole number of the thiol group in a polythiolcompound which may have one or more (poly)sulfide bonds in a molecule istaken as C.

TABLE 2 Reflec- Heat Maximum Tint- tive Abbe's Resis- Tensile Specificability Index Number tance stress Gravity (% T565 Examples (ne) (ve) (°C.) (N/mm²) (20° C.) nm) Example 1 1.597 41 105 96 1.28 19 Example 21.594 41 111 101 1.28 37 Example 3 1.599 41 111 92 1.28 32 Example 41.594 41 109 93 1.29 34 Example 5 1.594 41 116 104 1.29 52 Example 61.587 42 105 92 1.27 12 Example 7 1.596 40 100 101 1.28 28 Compara-1.598 41 117 88 1.31 56 tive Example 1

From the above results, it was found that the resins of Examples areexcellent in tintability and resin strength, as compared to that of theComparative Example, achieving the balance of the refractive index,Abbe's number, heat resistance and specific gravity.

1. A polymerizable composition containing (A) an alicyclic isocyanatecompound represented by the following formula (1) and/or the followingformula (2),

(in the formula (1), n=1)

wherein the alicyclic isocyanate compound of formula (2) is1,3-bis(isocyanatomethyl) cyclohexane, (B) an isocyanate compoundcontaining at least one selected from a group of compounds consisting ofthe following formula (3) and the following formula (4),OCN—(CH₂)m-NCO  (3) wherein the compound of formula (3) is selected fromthe group consisting of 1,2-ethylene diisocyanate, 1,3-propylenediisocyanate, 1,4-butylene diisocyanate, 1,6-hexamethylene diisocyanate,1,7-heptamethylene diisocyanate, 1,8-octamethylene diisocyanate,1,9-nonamethylene diisocyanate, and 1,10-decamethylene diisocyanate

(in the formula (4), p=6) (C) at least one polythiol compound which mayhave one or more (poly)sulfide bonds in a molecule, and (D) at least onepolyhydroxy compound having two or more hydroxy groups in a moleculeand/or at least one (poly)hydroxy(poly)mercapto compound having one ormore hydroxy groups and one or more thiol groups, wherein 100×A/(A+B+C)is not less than 0.1% but not more than 30% when the mole numbers of thehydroxy group and the thiol group in said (D) polyhydroxy compoundhaving two or more hydroxy groups in a molecule and/or the(poly)hydroxy(poly)mercapto compound having one or more hydroxy groupsand one or more thiol groups are respectively taken as A and B, and themole number of the thiol group in said (C) polythiol compound which mayhave one or more (poly)sulfide bonds in a molecule is taken as C, andwherein the mole ratio of the component (B) to the component (A) isequal to or larger than 0.084 and equal to or smaller than 0.25.
 2. Thepolymerizable composition as set forth in claim 1, wherein said (A) isan alicyclic isocyanate compound represented by the following formula(6) and/or said formula (2), and

said (B) is at least one isocyanate compound selected from a group ofcompounds consisting of said formula (3) (1,6-hexamethylenediisocyanate) and said formula (4) (p=6).
 3. The polymerizablecomposition as set forth in claim 1, wherein said (C) polythiol compoundwhich may have one or more (poly)sulfide bonds in a molecule contains atleast one of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane,2,5-bismercaptomethyl-1,4-dithiane, bis(mercaptoethyl)sulfide,1,1,3,3-tetrakis(mercaptomethylthio)propane,4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane,5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane and4,7-dimercaptomethyl-1,11 -dimercapto-3,6,9-trithiaundecane.
 4. Thepolymerizable composition as set forth in claim 1, wherein said (D)polyhydroxy compound having two or more hydroxy groups in a moleculeand/or the (poly)hydroxy(poly)mercapto compound having one or morehydroxy groups and one or more thiol groups contains at least one of2-mercaptoethanol, 3-mercapto-1,2-propanediol, pyrogallol, ethyleneglycol and polycaprolactonediol.
 5. The polymerizable composition as setforth in claim 4, wherein said (A) is an alicyclic isocyanate compoundrepresented by the following formula (6) and/or said formula (2),

said (B) is at least one isocyanate compound selected from a group ofcompounds consisting of said formula (3) (1,6-hexamethylenediisocyanate) and said formula (4) (p=6), said (C) polythiol compoundwhich may have one or more (poly)sulfide bonds in a molecule is at leastone of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane,4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane,5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane and4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and said (D)polyhydroxy compound having two or more hydroxy groups in a moleculeand/or the (poly)hydroxy(poly)mercapto compound having one or morehydroxy groups and one or more thiol groups is 2-mercaptoethanol.
 6. Amethod for producing a resin, comprising polymerizing the polymerizablecomposition as set forth in claim 1.